Voice activity detection (VAD), also known as speech activity detection or speech detection, is a technique used in speech processing in which the presence or absence of human speech is detected. The main uses of VAD are in speech coding and speech recognition. VAD can facilitate speech processing, and can also be used to deactivate some processes during identified non-speech sections of an audio session. Such deactivation can avoid unnecessary coding/transmission of silence packets in Voice over Internet Protocol (VOIP) applications, saving on computation and on network bandwidth.